The blockbuster bout has been announced for Saturday May 22.
Taylor, 30, currently holds the WBA and IBF versions of the title while Mexico’s Ramirez is the WBC and WBO champion.
Both boxers are unbeaten, with Taylor boasting 13 knockouts from his 17 bouts. Ramirez has 17 KOs from 26 fights.
“I’m excited it’s been finalised and over the line,” said Taylor.
"I can't wait to get in there for the biggest fight of my career. Fighting for the undisputed title is something all boxers dream about.”
Taylor, from Prestonpans, East Lothian, is aiming to be become Scotland’s first undisputed world champion since the legendary Ken Buchanan in the 1970s.
Ramirez, 28, is also striving to make history. “I look forward to making history by becoming the first boxer of Mexican descent to hold all four major world title belts,” he said.